I've gone down the Chocolate Highway. My only reaction was, "Well, that was OK." It isn't bad by any means. I suppose it was what one would call "successful" anal sex; we both enjoyed it, but I think less than vaginal sex. Given the better alternatives and the need for prep and lube, it's a bit cumbersome. It just doesn't seem worth the hassle, and it certainly isn't worth the desire that men invest in it. If women were to suddenly all agree that they were totally down with the buttsex, I think the appeal to men would dissipate fairly quickly. Not to zero, but the main appeal is that it isn't to be done, and certainly not by "nice girls." As for the other end...no one's ever tried it. I'm slightly curious since people swear by it and all, but it's not like I'm clammoring for someone to stick the pointer up my pooper. And who would want to? I mean, that place is a warzone. Vicious things come out of there. You don't. The end. Seriously, don't be that guy. You'll have way more fun doing what she's actually enthusiastic about.
The trick to getting anal if your girl is unwilling is to hold her down and force her. A few short meetings with a DA later and you'll be paired up with a large black man more than willing to fuck you in the ass.